Effect of age and food intake on dietary carbon turnover recorded in sheep wool.
Effect of age and food intake on dietary carbon turnover recorded in sheep wool.
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DOI：
10.1002/rcm.3693
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发表时间：
2008-09
期刊：
影响因子：
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通讯作者：
A. Zazzo;A. Moloney;F. Monahan;C. Scrimgeour;O. Schmidt
中科院分区：
文献类型：
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作者：
A. Zazzo;A. Moloney;F. Monahan;C. Scrimgeour;O. Schmidt
我们介绍了一系列绵羊控制饲喂实验的结果，旨在研究年龄和食物摄入量水平对将饲料碳信号纳入羊毛的动力学的影响。四个不同的组，每组三只羊，年龄从6到78个月不等，被喂以C(3)饮食，并转换为C(4)饮食，最长250天。为了达到不同的生长速度(高、低、无生长)，给每个组提供不同数量的相同的C(4)日粮。重复地从每只动物身上剪下羊毛并进行加工，以进行Delta(13)C分析。结果表明，在改变饮食习惯后，新长出的羊毛不会立即开始记录新饮食的同位素组成。时间间隔根据动物年龄的不同而不同，从羔羊的6+/-1天到年龄较大的母羊的15+/-4天。快速生长的羔羊的羊毛比生长缓慢的羔羊和小母羊的羊毛更快地接近平衡，其中老母羊的速度最慢。然而，转换饮食3周后，四组不同动物之间的羊毛Delta(13)C值的差异相对较小，不到两种饲料之间同位素差异的15%。这些结果表明，一个单一的方程可以用来重建不同年龄动物以前的饮食，前提是饮食相似，并且所有个体都处于正蛋白质平衡。
We present the results of a series of controlled feeding experiments with sheep, designed to investigate the effects of age and level of food intake on the kinetics of incorporation of the dietary carbon signal into wool. Four different groups of three sheep each, ranging in age from 6 to 78 months, were fed a C(3) diet and switched to a C(4) diet for up to 250 days. Different quantities of the same C(4) diet were provided to each group, in order to achieve different growth rates (high, low, and no growth). Wool was repeatedly shorn from each animal and processed for delta(13)C analyses. Results show that newly grown wool does not start recording the isotope composition of the new diet immediately after the diet-switch. The time-lag varies according to the age of the animal, from 6 +/- 1 days in lambs to up to 15 +/- 4 days in the older ewes. Wool from fast-growing lambs approached equilibrium faster than that from slow-growing lambs and young ewes, with old ewes being the slowest. However, 3 weeks after the diet-switch, the differences in wool delta(13)C values between the four different groups of animals were relatively small and represented less than 15% of the isotopic difference between the two diets. These results suggest that a single equation can be used to reconstruct previous diets for animals of different age, provided that the diet is similar and all individuals are in positive protein balance.